1. Field of the Invention
This invention relates generally to the field of oil and gas production. More specifically, the present invention relates to a shape charged system having a reinforced casing that enhances the structural integrity of the casing thereby minimizing associated fracturing of the casing during detonation of the shaped charge.
2. Description of Related Art
Perforating guns are used for the purpose, among others, of making hydraulic communication passages, called perforations, in wellbores drilled through earth formations so that predetermined zones of the earth formations can be hydraulically connected to the wellbore. Perforations are needed because wellbores are typically completed by coaxially inserting a pipe or casing into the wellbore, and the casing is retained in the wellbore by pumping cement into the annular space between the wellbore and the casing. The cemented casing is provided in the wellbore for the specific purpose of hydraulically isolating from each other the various earth formations penetrated by the wellbore.
Included with the perforating guns are shaped charges that typically include a housing, a liner, and a quantity of high explosive inserted between the liner and the housing. When the high explosive is detonated, the force of the detonation collapses the liner and ejects it from one end of the charge at very high velocity in a pattern called a “jet”. The jet penetrates the casing, the cement and a quantity of the formation.
Due to the high force caused by the explosive, the shaped charge often shatters into many fragments that exit the perforating gun into the fluids within the wellbore 5. These fragments can clog as well as damage devices such as chokes and manifolds, thereby restricting the flow of fluids through these devices and possibly hampering the amount of hydrocarbons produced from the particular wellbore 5. Therefore, there exists a need for an apparatus and a method for conducting perforating operations that reduces fragmentation of shaped charges and also provides a manner of retaining fragments of shaped charges produced during the perforation sequence.